| // Copyright (c) 2011, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| /// @assertion A constant expression is an expression whose value can never |
| /// change, and that can be evaluated entirely at compile time. |
| /// The potentially constant expressions and constant expressions are the |
| /// following: |
| /// . . . |
| /// • An expression of the form e1 + e2 is a potentially constant expression if |
| /// e1 and e2 are both potentially constant expressions. It is further a |
| /// constant expression if both e1 and e2 are constant expressions and either |
| /// both evaluate to an instance of int or double, or both evaluate to an |
| /// instance of String, such that ‘+’ denotes an instance operator invocation. |
| /// • An expression of the form -e1 is a potentially constant expression if e1 |
| /// is a potentially constant expression. It is further a constant expression |
| /// if e1 is a constant expression that evaluates to an instance of type int |
| /// or double, such that ‘-’ denotes an instance operator invocation. |
| /// • An expression of the form e1 - e2, e1 * e2, e1 / e2, e1 ~/ e2, e1 % e2, |
| /// e1 < e2, e1 <= e2, e1 > e2, or e1 >= e2 is potentially constant if e1 and |
| /// e2 are both potentially constant expressions. It is further constant if |
| /// both e1 and e2 are constant expressions that evaluate to instances of int |
| /// or double, such that the given operator symbol denotes an invocation of an |
| /// instance operator |
| /// |
| /// @description Checks that an expression of the form `e1 - e2` cannot be used |
| /// to initialize a constant variable if e2 is a string. |
| /// @author iefremov |
| |
| const m = 1 - "1"; |
| // ^ |
| // [analyzer] unspecified |
| // [cfe] unspecified |
| |
| main() { |
| print(m); |
| } |
